Classification

Question 1

What is biodiversity?

Answer 1

Measure of variety of living organisms and their genetic differences.

Question 2

What are the rules of the binomial system for classification?

Answer 2

• italics
• genus name has upper-case letter, species name has lower-case e.g. Homo sapiens
• after first use, they’re abbreviated to initial of genus and then species name eg H. sapiens

Question 3

What are the domains?

Answer 3

Archaea, Bacteria, Eukaryota

Question 4

What does the Archaea domain contain?

Answer 4

Archaebacteria: ancient bacteria thought to be early relatives of eukaryotes, extremophiles included!! asexual

Question 5

What does the bacteria domain contain?

Answer 5

Eubacteria: true bacteria, cyanobacteria. asexual

Question 6

What does the eukaryota domain contain?

Answer 6

Protoctista: microscopic organisms. Some are heterotrophs, some autotrophs.
Fungi: all heterotrophs, mostly live on dead things. They ahve chitin in their cell walls.
Plantae: almost all autotrophs, making food using psynthesis.
Animalia: heterotrophs that move their whole bodies during at least one stage of life cycle. Invertebrates, and vertebrates.

Question 7

What are all the main taxonomic groupings?

Answer 7

Domain, kingdom, phylum/division, class, order, family, genus, species. DK Police Department can’t offer feds government secrets.

Question 8

What was the morphological species concept and why didn’t it work?

Answer 8

Based on categorizing using appearance of organisms. But appearance of organism can be affected by many things and there can be lots of variation within a group of closely related organisms. Also sexual dimorphism (female/male differences)

Question 9

What was the original reproductive concept for classification? What was wrong with it?

Answer 9

A group of organisms with similar characteristics that interbreed to produce fertile offspring.
But not all of the organisms in a species can interbreed because they don’t all live in the same area. Also in some cases, different species can sometimes reproduce to give fertile offspring.

Question 10

What are the two revised new reproductive concepts for classification?

Answer 10

• group of organisms with similar characteristics that are all potentially capable of breeding to produce fertile offspring
• group of organisms in which genes can flow between individuals

Question 11

What’s a weakness in the new revised reproductive concept for classification?

Answer 11

Doesn’t help to classify plants because they frequently interbreed with similar species to form fertile offspring.

Question 12

What is the ecological species model and why is it weak?

Answer 12

based on ecological niche occupied by an organism. Niche definitions vary and many species occupy more than one niche.

Question 13

Why is the original reproductive concept good?

Answer 13

Overcomes issues like sexual dimorphism and is a good working definition for many animal species.

Question 14

What is the mate-recognition species model and why is it weak?

Answer 14

Based on unique fertilisation systems like mating behaviour. But many species will mate or cross-pollinate other species and may even produce fertile offspring but are still different species.

Question 15

why is classification important? (4)

Answer 15

• One organism will have different names in different countries/areas - we need to be sure we’re referring to the same organism.
• Biodiversity is very important, but to quantify it we need to identify different groups of organisms.
• Helps scientists monitor how populations change.
• Helps biologists understand how different types of living organisms are related.

Question 16

What is the genetic species model and why is it weak (2) (and strong (1))?

Answer 16

Based on DNA.
People still have to decide how much genetic difference makes two organisms members of different species. Collecting DNA used to be hard and long and expensive to analyse.
It’s getting cheaper now?

Question 17

What is the evolutionary species model and why is it weak and strong?

Answer 17

Based on shared evolutionary relationships between species, members have shared evolution and are evolving together. Biologically sound!
Not easy to apply - not always clear evolutionary pathway for one organism.

Question 18

Limitations of species models? (4)

Answer 18

• Finding evidence. Setting up breeding program is time-consuming ,expensive and may be useless.
• Plants of different closely related species interbreed to produce fertile hybrids - when should the hybrids be regarded as a separate species?
• Many organisms don’t reproduce sexually - reproductive models are irrelevant for bacteria fungi etc
• Fossil organisms can’t reproduce and we often don’t have accessible DNA of them, but they need classification.

Question 19

What does DNA barcoding involve?

Answer 19

Looking at short genetic sequences from a part of the genome common to particular groups of organisms.

Question 20

What is DNA profiling?

Answer 20

Process where non-coding areas of DNA are analysed to identify patterns.

Question 21

How do lice show us anything about our ancestry?

Answer 21

Humans had head lice with chimpanzee louse ancestors, pubic lice with gorilla louse ancestors before the body lice evolved, meaning before we started wearing woven clothes.

Question 22

What is molecular phylogeny?

Answer 22

Analysing structures of many different chemicals and DNA to identify relationships between groups of organisms.

Question 23

What happens in gel electrophoresis for DNA identification?

Answer 23

Chemicals are placed in wells in a gel medium in a buffer, with known DNA/RNA fragments.
The big DNA molecules are cut into fragments by restriction endonuclease that cut DNA into fragments at specific sites - they’re added to a dyed gel which binds to the fragments and fluoresces under UV light.
A dye is added to the DNA too, and it moves slightly faster to show when to turn the machine off.
A current is passed through the apparatus, DNA fragments move towards positive anode, moving at different rates depending on mass and charge.

Question 24

Why does the DNA fragment move towards the positive anode?

Answer 24

Because of the negative charge on the phosphate groups in the DNA

Question 25

What happens in gel electrophoresis for amino acid identification?

Answer 25

Ninhydrin is added to the gel after electrophoresis, which reacts with the amino acids so they show up as patches.

Question 26

What is conservation?

Answer 26

Keeping and protecting a living and changing environment

Question 27

What does ex-situ conservation involve?

Answer 27

Conservation of components of biology diversity outside their natural habitats.

Question 28

What are the good things about seed banks?

Answer 28

The seeds stored may germinate in many hundreds of years time,
they can collect seeds without damaging the natural population,
many can be stored in a small space,
they contain all the genetic material of the plant so they are a record of the genetic make-up of species

Question 29

Why use field gene banks? What’s bad/good about this?

Answer 29

Because some seeds do not store well, so they’re grown in plantations or as tissue cultures. They can take up a lot of room if they’re plantations, but using tissue cultures allows you to store with less space and time.

Question 30

What are the problems with captive breeding and reintroduction? (6)

Answer 30

• not enough space of resources in zoos for all the endangered species
• hard to provide right conditions for breeding
• reintroduction to wild will be unsuccessful unless the original reason for species being near extinction is removed
• animals in captivity may have problems adjusting to life in the wild
• when the population is small, gene pool is reduced, causing problems
• reintroduction programs can be expensive and long, and may fail

Question 31

How can in-situ conservation take place? (2)

Answer 31

• habitat restoration and recovery

- strategies for sustainable use and management of resources

Question 32

What is in-situ conservation?

Answer 32

Conservation of ecosystems and natural habitats, and the maintenance and recovery of viable populations of species in their natural surroundings.